Jens Axboe <axboe@xxxxxxxxx> writes:
> From: Christoph Hellwig <hch@xxxxxx>
>
> Just call blk_poll on the iocb cookie, we can derive the block device
> from the inode trivially.
Does this work for multi-device file systems?
-Jeff
>
> Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
> ---
> fs/block_dev.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index e1886cc7048f..6de8d35f6e41 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -281,6 +281,14 @@ struct blkdev_dio {
>
> static struct bio_set blkdev_dio_pool;
>
> +static int blkdev_iopoll(struct kiocb *kiocb, bool wait)
> +{
> + struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host);
> + struct request_queue *q = bdev_get_queue(bdev);
> +
> + return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait);
> +}
> +
> static void blkdev_bio_end_io(struct bio *bio)
> {
> struct blkdev_dio *dio = bio->bi_private;
> @@ -398,6 +406,7 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
> bio->bi_opf |= REQ_HIPRI;
>
> qc = submit_bio(bio);
> + WRITE_ONCE(iocb->ki_cookie, qc);
> break;
> }
>
> @@ -2070,6 +2079,7 @@ const struct file_operations def_blk_fops = {
> .llseek = block_llseek,
> .read_iter = blkdev_read_iter,
> .write_iter = blkdev_write_iter,
> + .iopoll = blkdev_iopoll,
> .mmap = generic_file_mmap,
> .fsync = blkdev_fsync,
> .unlocked_ioctl = block_ioctl,
